LOS ANGELES -- Sen. John McCain, R-Ariz., Wednesday restated his opposition to pulling U.S. troops from Iraq now, and criticized Democratic presidential hopefuls on the issue.

"Those who claim we should withdraw from Iraq in order to fight al-Qaida more effectively elsewhere are making a dangerous mistake," the presumptive Republican nominee told the Los Angeles World Affairs Council. "I believe a reckless and premature withdrawal would be a terrible defeat for our security interests and our values."

Democratic Sens. Barack Obama and Hillary Clinton, battling to be their party's presidential nominee, have both said they would begin withdrawing combat troops soon after taking office, if elected.

Taking such a course, McCain said, "would eventually draw us into a wider and more difficult war that would entail far greater dangers and sacrifices than we have suffered to date."

Outlined his foreign policy, McCain said the United States must aggressively regain its former global stature and take the lead in environmental protection.

"I know it is incumbent on America ... to lead in building the foundations for a stable and enduring peace," he said, "a peace built on the strength of our commitment to it ... and on our courage and wisdom to make hard choices."